![]() ![]() That means that if measurements of peat accumulation were taken near the center and used to extrapolate an overall accumulation rate, that could result in a severe overestimate of that area’s ability to sequester greenhouse gases. For example, they found that the peat forms domes whose growth is greatest at the center and tapers off toward the edges. The study revealed significant aspects of the way peatlands form and grow that could be important for evaluating future effects of climate change or land-use changes. In addition, changes in rainfall patterns that may occur as a result of climate change - with rainfall more concentrated in rainy and dry seasons rather than evenly distributed - could kill off many of the trees that dominate these lands. Encroachment of saltwater into peatland that had formerly been saturated with freshwater could kill off trees and other vegetation. By midcentury, that land may be lost” due to sea-level rise. ![]() But most of these peatlands, Harvey says, “are pretty close to sea level. When peatland forests are cut down and drained, the water table in the area drops. Getting into the site from the coast to collect data and maintain the facility required a long boat trip along a crocodile-inhabited river followed by an hours-long trek through the forest. In order to get accurate ongoing measurements of conditions in the peatland, from the water table on up to the forest canopy, the team built an observation tower by taking sections of old, kilometer-long oil pipeline and pounding them vertically deep into the soft ground. “The long-term motivator for this work,” he says, is that “if we could understand how these peat forests actually accumulate peat, maybe we could preserve some of them or regenerate peat forest on damaged land.” “It is remarkable how much the peat forests are just gone everywhere else.”īy studying this undisturbed tract, he says, the researchers were able to see how peatlands function under normal conditions, to provide a baseline for better understanding as the lands change. “We found this site that still has peat growing,” he says, partly because that petroleum-rich nation has been able to resist the economic draw of the palm-oil market. Harvey and his team have found one of the last undisturbed tropical peat forests, in the nation of Brunei on the island of Borneo. (Peat that gets buried and compressed underground is the material that ultimately turns to coal). Tropical peatlands, unlike those in temperate zones that are dominated by sphagnum moss, are forested with trees that can tower to 150 feet, and peat fires can sometimes ignite forest fires that consume these as well. Tropical peatlands may contain as much carbon as the amount consumed in nearly a decade of global fossil fuel use, and raging peat fires in Indonesia alone have been estimated in some years to contribute 10 to 40 percent as much greenhouse gas to the atmosphere as all the world’s fossil fuel burning. Sometimes the exposed peat can actually catch fire and burn for extended periods, causing massive clouds of air pollution. Once deforested and drained, the peatland dries out, and the organic (carbon-containing) soil oxidizes and returns to the atmosphere. “There is a tremendous amount of peatland in Southeast Asia, but almost all of it has been deforested,” says Harvey, who is a professor of civil and environmental engineering and has been doing research on that region for several years. The findings are described this week in the journal Proceedings of the National Academy of Sciences, in a paper by MIT Professor Charles Harvey, research scientist Alexander Cobb, and seven others at MIT and other institutions. The net result is that these former carbon sinks, which have taken greenhouse gases out of the atmosphere, are now net carbon sources, instead accelerating the planet’s warming. Now, research shows peatlands face another threat, as climate change alters rainfall patterns, potentially destroying even forested peatlands that remain undrained. But such forests have been disappearing fast due to clear-cutting and drainage projects making way for plantations. Tropical peat swamp forests, which once occupied large swaths of Southeast Asia and other areas, provided a significant “sink” that helped remove carbon dioxide from the atmosphere. ![]()
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